Quantitative pulse measurement devices (QPMDs) are deployed in numerous fields including the measurement of photons and particles (e.g., beta particles). QPMDs are typically provided with detectors which are capable of detecting events, such as the interaction of a photon or a particle with the detector, and producing a pulse which is to be measured. This pulse can require subsequent amplification before it is measured. When the pulse is measured, various properties of the pulse may be of use, including in particular the frequency of the pulses, yielding a count rate typically measured in counts per second (cps). Other properties of interest may include the pulse height, or the correlation of the pulse with other events.
When the measurement of count rates is of interest, QPMDs must generally deploy a “dead-time correction” (DTC) scheme. Dead-time correction is the adjustment of measured values to correct for measurements lost due to system processing time. There are many well-documented schemes for dead-time correction with varying degrees of accuracy by counting the amount of “elapsed dead time” (or its inverse, “elapsed live time”) using high-speed clocks, with the accuracy limited by the duration of one clock cycle. However, high-speed clocks consume significant amounts of power. For a system that needs dead-time correction and low power consumption, such as a portable electronic dosimeter, an alternative approach is needed.
In addition, under uniform signal inputs (i.e., signal inputs that do not change with time), it is often possible to estimate the dead time correction with fair accuracy by knowing the relationship between the fixed signal input and the system performance. However, non-uniform signal inputs make this kind of estimation inaccurate in ways that cannot be predicted a priori.
Therefore, there is a need for a dead-time correction system and method that reduce or eliminate the problems described above.